Librewolf is a tiny niche within a tiny niche. No one at Google has even heard of it, and they’re certainly not going to start throwing money at a tiny obscure browser fork with zero web engine development experience if Firefox dies. Librewolf is a cool project, and I will gladly recommend it, but it dies with Firefox. It only even makes sense to consider the possibility if you have absolutely no self awareness of how small of a community we are at all.
Lemmy is very much not gigantic. It has tens of thousands of acitve users. Reddit has hundreds of millions. Librewolf is even more niche than Lemmy is. Librewolf isn’t even really a browser, it’s just a small patchset for Firefox. It only has it’s own name and logo because Mozilla doesn’t like people distributing modified versions of Firefox with their branding attached. Librewolf is very cool, but jumping straight from that to full on taking Gecko maintenance on completely is just a silly idea. I hope that if Mozilla does fail someone takes over Firefox from them, but Mozilla isn’t running out of Google money any time soon, and Librewolf isn’t even likely to be who takes it over if it does happen. It’s way more likely to end up in the hands of a big Linux distro, or even a new organization formed specifically for the purpose of taking Firefox over. All this talk of Librewolf being the savior of Gecko based browsers is completely disconnected from the reality of what Librewolf is.